An Ebola vaccine candidate tested in Guinea showed 100% efficacy in individuals upto now, according to a release by the World Health Organisation. The results from an analysis of the Guinea Phase III vaccine trial for efficacy showed that VSV-EBOV vaccine was highly effective against Ebola.

“This is an extremely promising development," said Margaret Chan, director-general of the World Health Organization, in a statement. “An effective vaccine will be another very important tool for both current and future Ebola outbreaks," Chan added.

The VSV-EBOV was developed by the Public Health Agency of Canada, and licensed to NewLink Genetics which entered into an exclusive worldwide licensing agreement with Merck. Merck would carry out the research, development, manufacture, and distribution of the investigational vaccine.

Although the vaccine up to now shows 100% efficacy in individuals, more conclusive evidence is needed on its capacity to protect populations through what is called herd immunity. The Guinean national regulatory authority and ethics review committee have approved continuation of the trial.

The trial is being implemented by the Guinean authorities, WHO, Médecins sans Frontières (MSF) and the Norwegian Institute of Public Health, with support from a broad partnership of international and national organizations.

“This is a remarkable result which shows the power of equitable international partnerships and flexibility," said Jeremy Farrar, director of the Wellcome Trust, one of the funders of the trial. “This partnership also shows that such critical work is possible in the midst of a terrible epidemic," added Farrar.